Petrovic stumbled to a 7-over 77 and tumbled into a share of 29th at plus-2.

Swafford entered the day two strokes behind first-round co-leaders Kim and Petrovic, but made up that difference during his front nine with a couple of birdies at the first and sixth.

After stumbling to a bogey at the ninth, he raced to the top of the leaderboard with a streak of four straight birdies from the 11th.

He gave two of those strokes back with a double bogey at the par-4 15th, but recovered with a birdie at the last to hit the clubhouse with the outright lead at 7-under.

"I made a couple of bad swings and made some bad numbers. You miss it in the wrong spot and you've got to get it back in play fast. Those were unfortunate errors, but I rebounded nicely," Swafford said of his double bogey. "The greens are getting firmer and faster and the rough's not getting any shorter. I just tried to keep it in play and stick to my game plan."

Putnam birdied the par-5 second, then converted back-to-back birdies at five and six to move to minus-2.

Around the turn, Putnam again had consecutive birdies at 10 and 11. He moved to 5-under for the event with a birdie on the par-4 14th. Putnam gave that back as he bogeyed the 16th, however he quickly atoned for that mistake with a birdie on No. 17. He parred the last to end two back.

Collins played the back nine, his first nine, with bogeys at 11 and 15, then back-to-back birdies at 16 and 17. On the front side, he poured in three consecutive birdie efforts from the second to move to minus-5.

The two-time winner on the Web.com Tour faltered to a bogey at the sixth, but came right back with a birdie at seven. He parred the last two to share second.

Kang, like Collins, played the back nine first and he opened with birdies at 10 and 14. Kang tripped to a double-bogey on the par-3 17th to slide back to minus-3.

The Korean wrapped bogeys at one and three around a birdie on the second. At the long par-4 sixth, Kang holed out for eagle, then birdied the ninth, his last, to end at minus-5.

NOTES: Putnam took over the top spot on the money list with a win last week in Mexico ... Chad Moseley and Michael Letzig both withdrew during their second round, raising the total to eight players that withdrew in the first two rounds ... The tour minimum of 60 players made the cut at 3-over 143 ... Among those that missed the cut were Danny Lee, Billy Andrade, Edward Loar and Lee Janzen.